What are the features of a type IV pfd?

A Type IV personal flotation device (PFD) is designed for specific uses, primarily as a throwable device, rather than for continuous wear. Key features include a buoyant design that allows it to be thrown to a person in distress, typically consisting of a cushion or ring shape. It must be easily accessible and visible in emergencies, and while it provides buoyancy, it does not offer the same level of security or support as wearable PFDs. Type IV PFDs are often required on boats, complementing other safety equipment.